Macedonia’s president said on Wednesday he would not sign a landmark deal reached with Greece on changing his country’s name, dashing hopes of a swift end to a diplomatic dispute that has blocked its bid to join the European Union and Nato.

In Greece, the prime minister, Alexis Tsipras, faced a barrage of criticism and the prospect of a no-confidence vote against his government as he and Macedonian prime minister Zoran Zaev announced the accord late on Tuesday.